/*************************************************************************
    > File Name: dbm1.c
    > Author: liyisheng
    > Mail: liyishengchn@gmail.com 
    > Created Time: Sun 03 May 2015 01:23:16 PM CST
 ************************************************************************/

#include<stdio.h>
#include<stdlib.h>
#include<unistd.h>
#include<fcntl.h>

#include<ndbm.h>

#include<string.h>

#define TEST_DB_FILE "/tmp/dbm1_test"
#define ITEMS_USED 3

struct test_data
{
	char misc_chars[15];
	int any_integer;
	char more_chars[21];
};

int main()
{
	struct test_data items_to_store[ITEMS_USED];
	struct test_data item_retrieved;

	char key_to_use[20];
	int i, result;

	datum key_datum;
	datum data_datum;

	DBM* dbm_ptr;

	dbm_ptr = dbm_open(TEST_DB_FILE, O_RDWR | O_CREAT, 0666);
	if(!dbm_ptr)
	{
		fprintf(stderr, "Failed to open database\n");
		exit(EXIT_FAILURE);
	}

	memset(items_to_store, '\0', sizeof(items_to_store));
	strcpy(items_to_store[0].misc_chars, "First");
	items_to_store[0].any_integer = 47;
	strcpy(items_to_store[0].more_chars, "foo");

	strcpy(items_to_store[1].misc_chars, "bar");
	items_to_store[1].any_integer = 13;
	strcpy(items_to_store[1].more_chars, "unlucky?");

	strcpy(items_to_store[2].misc_chars, "Third");
	items_to_store[2].any_integer = 3;
	strcpy(items_to_store[2].more_chars, "baz");
	
	for(i = 0; i < ITEMS_USED; ++i)
	{
		sprintf(key_to_use, "%c%c%d",
				items_to_store[i].misc_chars[0],
				items_to_store[i].more_chars[0],
				items_to_store[i].any_integer);

		key_datum.dptr = (void *)key_to_use;
		key_datum.dsize = strlen(key_to_use);

		data_datum.dptr = (void *)&items_to_store[i];
		data_datum.dsize = sizeof(struct test_data);


		result = dbm_store(dbm_ptr, key_datum, data_datum, DBM_REPLACE);
		if(result != 0)
		{
			fprintf(stderr, "dbm_store failed on key %s\n", key_to_use);
			exit(2);
		}
	}


	sprintf(key_to_use, "Ff%d", 47);

	key_datum.dptr = key_to_use;
	key_datum.dsize = strlen(key_to_use);

	data_datum = dbm_fetch(dbm_ptr, key_datum);
	if(data_datum.dptr)
	{
		printf("Data retrieved\n");
		memcpy(&item_retrieved, data_datum.dptr, data_datum.dsize);
		printf("Retrieved item - %s %d %s\n",
				item_retrieved.misc_chars,
				item_retrieved.any_integer,
				item_retrieved.more_chars);
	}else
	{
		printf("No data found for key %s\n", key_to_use);
	}
	dbm_close(dbm_ptr);
	exit(EXIT_SUCCESS);

}

